Cutter for flue-holes in tube-sheets of boilers



(No Model.)

W. P. HARRISON.

CUTTER FOR FLUE HOLES IN TUBE SHEETS OP BOILERS.

No. 818,897. Patented May 26, 1885.

WITNESSES: T M :77 mvENToR u. u u

wawem/ M linirrnn 'rn'rns \VLTLLIAM F. HARRISON, OF W'ILMIJGTON, DELA'WARE.

CUTTER FOR FLUE-HOLES IN TUBE-SHEETS OF BOILERS.

GPECIFICATION gunning part of Letters Patent No. 318,897, dated May 26, 1885.

(X0 model) To aZZ whom it may concern;

Be it known that I, \VILL'IAM F. HARRISON, a citizen of the United States, residing at \Vilmington, in the county of New Castle and State of Delaware, have invented certain new and usefulImprovements in Gutters for Flue- Holes in Tube Sheets of Boilers; and I do hereby declare the following to be a sui'ficiently full, clear, and exact description thereof as to enable others skilled in the art to make and use the said invention.

This invention relates to the tools used in making holes in tube-sheets of boilers and other plate'metal structures for the insertion of tubes, and has for its object the making of such tools readily adjustable to make openings of a greater range of diameters, a greater facility of making and introducing and adjusting the cutters of such hits, the more effective and secure clamping of the cutters when in use, and the accurate fitting of the central hole in the plates to the guide or central stem of the boring implement.

The nature of this invention to effect'these several desiderata may be briefly stated to consist of two transversely-adjustable slides having sockets for holding cutters and screws for longitudinally adjusting and holding the cutters therein, a clamping device for holding the slides combined with a central boring-bit for reaming the guiding hole in the plate and guiding the tool during the operation of the cutters.

I will now proceed to particularly describe the mode of making and using the said invention, referring in so doing to the drawings annexed, in which- Figure 1 shows an elevation of this invention; Fig. 2, abottom or inverted plan thereof; Fig. 8, a section thereof in the plane indicated by the dotted line a a: in Fig. 1; Fig. 4, a section thereof in a vertical plane indicated by the dotted lineyyin Fig. 2. Fig. 5 shows one of the cutters detached in front view; Fig. 6, one of the cutters in side view; 7, one of the cutters in end view; Fig. 8, a detached view of the central reaming-bit and guide; and Figs. 9, 10, and 11 show detached views of the tool-holders, illustrating the means of clamping the tools therein and the means for adjusting the tools lengthwise.

The same letters of reference apply to the same parts in the several'figures.

A represents a shank adapted to fit accurately into and be rotated by the spindle of a 5 5 -drilling-machine; B, the body cuttenhead cf cylindric form with openings and cavities therein, as hereinafter described.

0 is a screw-threaded portion of the shank A, upon which is fitted a nut, D.

E is a rectangular slot cut transversely and centrally through the cylindrical body B.

F F are recesses cut in body B, into which fit lugs G G, formed on the slides H H, fitted through the slot E, so as to fill the slot-E side 6 5 wise and to rest on the bottom thereof.

J is a cross-bar or clamp placed through the slot E above the slides H H, and of such form that the ends of the cross-bar rest one on each of the slides H H, and when forced downward by the nut D clamp the slides H H firmly against the bottom or" the slot E.

K K are cutters having cylindrical shanks fitting into correspondingly-shaped cavities in the lugs G G on the slides .H H, in which they are held by set-screws M M pressing laterally against them, and are adjusted vertically by set-screws N N, arranged to press downwardly upon the upper ends of the cutters K K. The lower ends of the cutters K K are flattened andbeveled,so that each presents a cutting-edge and a clearance back thereof, as indicated in Figs. 6, 7 of the drawings.

Cavities O 0, formed in the body 13, receive the set-screws N N when the implement is 85 contracted for cutting holes of the least diam eter.

P is a cylindrical centering-pin provided with cutting edges or teeth at the lower end and screwed centrally into the bottom of the body B.

The tool-holders H are preferably made in two parts, as shown in Figs. 10, 11, and 12, so that the parts containing the screw N for making the endwise adjustment of the cutters K may be removed and greater facility afforded in fitting in and removing the shafts of the cutters K from the cylindrical sockets in the tool-holders H.

The operation of this implement is as follows: The location and diameter of the several holes in a tube-sheet having been decided guide.

ameter by means of the slides H H, and are clamped by the nut D and clamp J forcing the slides firmly down against the bottom of the slot the cutters K K are turned in their sockets so as to present their cutting-edges to their work and then clamped by the set-screws M M and adjusted verticallyby thescrews NN, so that both cutters K K may operate equally. The adjustment of the cutters K K should be such that the sides of them do not touch the sides of the channels which they cut, excepting the angles of the front edge. The cutter is then placed in a drilLpress and the bit P bores a true cylindrical opening in the center of each intended flue-hole. The sides of the bit I? fitting the hole in the sheet steadies the bit in the plate of metal and the cutters cut a channel or ring through the metal concentric with the The operation of boring with the central bit P, beside securing a perfectly true and exact fit of the pin P in the plate,also removes all metal that has been overstrained in the punching operation and thereby buckled.

From the form of the cutters K K itwill be readily seen that any competent mechanic can forge and grind them into shape, and adjust ments as to length are readily made by the screws N N so that the action of the cutters is equalized.

Having described my invention, what I claim isforth.

2. In a tool for cutting flue-holes in tubesheets, the combination of two independently laterally sliding tool-holders, each provided with a screw for longitudinal adjustment of the cutters and a screw for holding the said cutters in proper angular adjustment with a clamping device arranged, as described, to hold a said tool-holders in adjustment and a central steadying pin or guide provided with cuttingteeth for the purpose of insuring a perfect fitting of the guide and hole in the plate, substantially as set forth and described.

3. In an implement for boring tube-sheets, the combination of cutting-tools K, having cylindrical shafts fitted into cylindrical sockets and adjustable both lengthwise and upon their axes therein and having endwise-adjusting screws and clamping devices arranged, as described,for holding said tools in adjustment in the sockets witha clamping device for clamping said sockets in radial adjustment to a central boring and steadying bit, P, substantially as shown and described.

WM. F. HARRISON.

Witnesses:

HARVEY B. VANDEGRIFT, JOSEPH XV. VANDEGRIFT. 

